Affinities: In New Zealand, Frullania fugax appears morphologically similar to F. media and is discussed under that species. Previously, Hattori (1979b, 1987b) stated that this species seems most closely related to F. yorkiana Steph. However, Frullania yorkiana is one of several species, including F. baileyana, F. belmorensis, F. cataractama, which are only known from the type collections or the sterile state. With further collections, all of these species may yet prove to be conspecific with F. fugax, and are listed under dubious species at the conclusion of this treatment. Certainly, at least from the scant material available of the type specimens, the gametophytes appear to be very similar. However, in the absence of further collections, particularly of the perianths it is difficult to arrive at any formal conclusions.

Geographic distribution & ecology:

Distributed throughout Australasia (Fig. 7.1), including throughout the New Zealand botanical region. Of the New Zealand species, F. fugax is common on rotting wood or logs and is commonly found with gemmae or propagula.

Notes: Frullania fulfordiae is reduced to a synonym of F. fugax because all of the salient characters used to recognise it such as the toothed lateral margin of the stem underleaf are present in F. fugax, and there appears to be no correlation with geography or any other characters.